Open source repo

What's inside openai/codex

openai/codex is a Rust repo with 2,310,690 lines written in 4,202 files. codex is built with axum and uses SQLite and Sentry. AI signed 2.8% of the 13,064 commits of codex.

Its description on GitHub: “Lightweight coding agent that runs in your terminal”

RustApache-2.0133,007

Read on November 3, 2026, at commit f1b0721.

What the card proved: what it’s built with on the left, what it uses on the right.

See each one with its proof

More on this repo

TechnologiesWhat is codex built with?codex is built with axum and uses SQLite and Sentry.Who writes itHow much of codex did AI write?2.8%AI signed 2.8% of the 13,064 commits of codex.

In figures

lines written: 2,310,690; The ones people and agents wrote: product, tests, schemas and tooling. Generated code doesn’t count.
files: 4,202; The product’s, not counting tests.
test files: 2,441; The files that test the code.
technologies: 3; Each service with the file and line that prove it.

SeeRepo read the facts in its code and kept none of it. AI only helps sort its packages and folders by their names, and never sees its code.

Frequently asked questions

What is openai/codex?

openai/codex is a Rust repo with 2,310,690 lines written in 4,202 files. Its description on GitHub: “Lightweight coding agent that runs in your terminal”

The proof: its page on GitHub

What is codex built with?

codex is built with axum and uses SQLite and Sentry.

The proof: each service with its file and line

How much of codex did AI write?

AI signed 2.8% of the 13,064 commits of codex.

The proof: the commits each tool signed

What license does codex have?

codex is released under the Apache-2.0 license.

The proof: its page on GitHub

How many stars does codex have on GitHub?

codex had 133,007 stars on GitHub on November 3, 2026.